1. Field of the Invention
The present invention relates generally to a multi-fiber connector assembly for use within a fiber optic network, and more specifically, to a multi-fiber connector assembly including a multi-fiber ferrule, force centering structure and guard fibers to facilitate polishing.
2. Technical Background of the Invention
The development of fiber optic networks has created the need for readily connecting a plurality of optical fibers simultaneously at a single connection point. In this regard, multi-fiber ferrules are being developed to mate large numbers of optical fibers to deliver “fiber-to-the-curb” (FTTC), “fiber-to-the-business” (FTTB), “fiber-to-the-premises” (FTTP), and “fiber-to-the-home” (FTTH), collectively referred to generically herein as “FTTx.”
Fiber optic plug assemblies are typically mounted onto the ends of optical fiber cables. Single fiber connectors are typically used to terminate single fiber drop cables, while multi-fiber connectors are typically used to terminate cables include large numbers of individual optical fibers, and more commonly, ribbon fibers. Plug assemblies are typically received and aligned within adapter sleeves retained within fiber optic receptacles. In the case of multi-fiber ferrules, they are typically grossly aligned within receptacles and precisely aligned using guide pins retained within guide pin bores defined in the ferrule end face. Typically, ferrules of like configuration are mated and one mating connector is pre-loaded with the guide pins and the other mating ferrule defines guide pin bores for receiving the guide pins of the other ferrule during mating. Ferrules are also typically biased within the plug assemblies, thus allowing some movement of the ferrule during mating. Typically, plug assemblies include a substantially cylindrical plug body including the ferrule disposed within the plug body. In various connectors, the end of the plug body is open, or is provided with one or more openings, such that the ferrule is accessible within the plug body, such as to be cleaned, etc.
Several different types of conventional connectors have been developed, examples of which include, but are not limited to, SC, ST, LC, DC, MTP, MT-RJ, and SC-DC connectors. The size and shape of the ferrule of each of these connectors are somewhat different. Correspondingly, the size and shape of the alignment sleeve and plug body of each of these connectors are somewhat different. As a result, different receptacles and plugs are used in conjunction with different connectors and/or ferrules. In this regard, the receptacles typically define different sized and shaped internal cavities corresponding to the different sizes and shapes of the alignment sleeves and plug bodies received therein, and, in turn, corresponding to the different sizes and shapes of the ferrules of the connectors to be inserted into the alignment sleeves.
In addition to requiring the use of different receptacles and plugs based on the particular type of connector, conventional receptacle and plug assemblies are typically not compact enough to accommodate high density installations. Likewise, conventional smaller receptacle and plug assemblies are typically not able to withstand the relatively high tensile loads required for FTTx installations and are not able to handle mass interconnections. Exposure to adverse environmental conditions is also a significant issue as current network plans suggest that receptacles may remain unoccupied (i.e. without mated plugs) for an extended period of time. Thus, all receptacle and plug assemblies must be strong, durable, and robust.
As of yet, however, there is an unresolved need for a receptacle and plug assembly that utilizes an multi-fiber ferrule that can accommodate one or more stacks of fiber optic ribbon. There is also an unresolved need for a receptacle and plug assembly in which the ferrules and ferrule holders are “force centered” and “balanced,” such that the end faces of the ferrules are precisely aligned with one another during mating. This may be accomplished using the internal structure of a plug assembly. Further, there is an unresolved need for a receptacle and plug assembly that utilizes an multi-fiber ferrule with respect to which all of the optical fibers may be polished evenly, as current configurations often result in the “over polishing” of optical fibers disposed near the edges.